Gujō Hachiman Castle was first established under Endō Morikazu in 1559, then completed by his son Yoshitaka. After Endō Yoshitaka became a retainer to Oda Nobunaga, the castle was passed to Inaba Sadamichi, who constructed its donjon. Yoshitaka returned to rule the castle and surrounding district following the Battle of Sekigahara, and the fortifications were renovated and expanded once more under his descendant Tsunetomo from 1646. The castle was abandoned in 1870, with all but its stone walls torn down. The present donjon was reconstructed from wood in 1933, providing a fine vantage point over the attractive town below.